Which IC is used for demultiplexer?
1 Answer
A **demultiplexer (DEMUX)** is a digital electronic device used to route a signal from a single source to one of several outputs. Essentially, a demultiplexer takes one input signal and distributes it to one of many output lines, based on a set of control signals.
Several **integrated circuits (ICs)** can function as demultiplexers. The most common ICs used for demultiplexing tasks include:
### 1. **74LS138 (3-to-8 Line Decoder/Demultiplexer)**
- **Description**: The 74LS138 IC is a popular 3-to-8 line decoder, which also functions as a demultiplexer. It has three input lines, which are used as control signals, and can route the single input signal to one of eight output lines, depending on the combination of the inputs.
- **Pin Configuration**: This IC has 16 pins, and it uses active low output lines (the selected output is activated when it is low).
- **Use Case**: It’s widely used in applications where multiple output lines are needed, such as in memory addressing, signal routing, and other digital logic circuits.
### 2. **74HC138 (High-Speed CMOS 3-to-8 Line Decoder/Demultiplexer)**
- **Description**: This IC is very similar to the 74LS138 but uses CMOS technology, making it more power-efficient and faster in comparison to the LS series. It is also a 3-to-8 decoder that can act as a demultiplexer.
- **Pin Configuration**: It also has 16 pins and offers active-low outputs, and it's designed for better performance in terms of speed and low power consumption.
### 3. **74LS154 (4-to-16 Line Decoder/Demultiplexer)**
- **Description**: The 74LS154 is a 4-to-16 line decoder, which can be used as a demultiplexer to distribute one input signal to one of 16 output lines, depending on the four input control signals.
- **Pin Configuration**: This IC has 24 pins and provides active-low outputs. Like the 74LS138, it is often used in various digital systems to manage multiple outputs from a single source.
### 4. **74HC4514 (16-to-1 Line Multiplexer/Demultiplexer)**
- **Description**: The 74HC4514 IC is a 16-to-1 multiplexer, but it can also work as a demultiplexer when configured properly. It is capable of receiving one input signal and directing it to one of 16 output lines, based on the control signals.
- **Pin Configuration**: This IC is available in a 24-pin configuration, with active-low outputs for selecting which output to route the input signal to.
### 5. **CD74HC238 (3-to-8 Line Decoder/Demultiplexer)**
- **Description**: This IC is a 3-to-8 line decoder/demultiplexer that uses CMOS logic. It's commonly used in situations where you need a simple, efficient demux with a 3-bit control input to select one of the 8 output channels.
- **Pin Configuration**: It has 16 pins, and it provides active-low output channels, which means the selected output will be active when low.
### 6. **74LS251 (8-to-1 Multiplexer/Demultiplexer)**
- **Description**: The 74LS251 is an 8-to-1 multiplexer IC, which can also be used as a demultiplexer in certain configurations. It has 3 select lines and 8 output lines, allowing the signal to be routed from a single input to one of 8 outputs based on the select input.
- **Pin Configuration**: It has 16 pins and offers both active-low and active-high output lines depending on the input configuration.
### How These ICs Work in Demultiplexer Applications:
- **Control Lines**: The selection of output lines in a demultiplexer is based on the values of control (or address) inputs. These control lines dictate which output line should be active and receive the input signal.
- **Active-low Outputs**: Most demux ICs use active-low outputs, meaning the selected output will be low (0) while all other outputs are high (1).
- **Use in Digital Systems**: Demultiplexers are essential in systems where one signal needs to be routed to multiple locations, such as in memory systems (address decoders), communication systems (data routing), or control systems.
### Conclusion:
The **74LS138**, **74HC138**, and **74LS154** are among the most common ICs used for demultiplexing tasks. These ICs handle the basic demux operation by taking a single input signal and routing it to one of many outputs based on the input control signals. These ICs are commonly used in applications such as digital systems, memory addressing, signal routing, and multiplexing operations.
Several **integrated circuits (ICs)** can function as demultiplexers. The most common ICs used for demultiplexing tasks include:
### 1. **74LS138 (3-to-8 Line Decoder/Demultiplexer)**
- **Description**: The 74LS138 IC is a popular 3-to-8 line decoder, which also functions as a demultiplexer. It has three input lines, which are used as control signals, and can route the single input signal to one of eight output lines, depending on the combination of the inputs.
- **Pin Configuration**: This IC has 16 pins, and it uses active low output lines (the selected output is activated when it is low).
- **Use Case**: It’s widely used in applications where multiple output lines are needed, such as in memory addressing, signal routing, and other digital logic circuits.
### 2. **74HC138 (High-Speed CMOS 3-to-8 Line Decoder/Demultiplexer)**
- **Description**: This IC is very similar to the 74LS138 but uses CMOS technology, making it more power-efficient and faster in comparison to the LS series. It is also a 3-to-8 decoder that can act as a demultiplexer.
- **Pin Configuration**: It also has 16 pins and offers active-low outputs, and it's designed for better performance in terms of speed and low power consumption.
### 3. **74LS154 (4-to-16 Line Decoder/Demultiplexer)**
- **Description**: The 74LS154 is a 4-to-16 line decoder, which can be used as a demultiplexer to distribute one input signal to one of 16 output lines, depending on the four input control signals.
- **Pin Configuration**: This IC has 24 pins and provides active-low outputs. Like the 74LS138, it is often used in various digital systems to manage multiple outputs from a single source.
### 4. **74HC4514 (16-to-1 Line Multiplexer/Demultiplexer)**
- **Description**: The 74HC4514 IC is a 16-to-1 multiplexer, but it can also work as a demultiplexer when configured properly. It is capable of receiving one input signal and directing it to one of 16 output lines, based on the control signals.
- **Pin Configuration**: This IC is available in a 24-pin configuration, with active-low outputs for selecting which output to route the input signal to.
### 5. **CD74HC238 (3-to-8 Line Decoder/Demultiplexer)**
- **Description**: This IC is a 3-to-8 line decoder/demultiplexer that uses CMOS logic. It's commonly used in situations where you need a simple, efficient demux with a 3-bit control input to select one of the 8 output channels.
- **Pin Configuration**: It has 16 pins, and it provides active-low output channels, which means the selected output will be active when low.
### 6. **74LS251 (8-to-1 Multiplexer/Demultiplexer)**
- **Description**: The 74LS251 is an 8-to-1 multiplexer IC, which can also be used as a demultiplexer in certain configurations. It has 3 select lines and 8 output lines, allowing the signal to be routed from a single input to one of 8 outputs based on the select input.
- **Pin Configuration**: It has 16 pins and offers both active-low and active-high output lines depending on the input configuration.
### How These ICs Work in Demultiplexer Applications:
- **Control Lines**: The selection of output lines in a demultiplexer is based on the values of control (or address) inputs. These control lines dictate which output line should be active and receive the input signal.
- **Active-low Outputs**: Most demux ICs use active-low outputs, meaning the selected output will be low (0) while all other outputs are high (1).
- **Use in Digital Systems**: Demultiplexers are essential in systems where one signal needs to be routed to multiple locations, such as in memory systems (address decoders), communication systems (data routing), or control systems.
### Conclusion:
The **74LS138**, **74HC138**, and **74LS154** are among the most common ICs used for demultiplexing tasks. These ICs handle the basic demux operation by taking a single input signal and routing it to one of many outputs based on the input control signals. These ICs are commonly used in applications such as digital systems, memory addressing, signal routing, and multiplexing operations.